
where \(\rho _A=Tr_{\bar{A}}(\rho )\)  is the reduced density matrix for the subsystem \(A\) . It is shown that the EE contains short-distance divergence which satisfies an area law and hence the EE is a scheme-dependent quantity in the UV limit [1]}, [2]}. It is difficult to calculate the EE using QFT techniques. However, in the framework of the gauge/gravity duality, there is a simple prescription to compute entanglement entropy in terms of a geometrical quantity in the bulk [3]}, [4]}. According to this prescription, the holographic entanglement entropy (HEE) is given by
\(S_A=\frac{\rm {Area}(\Gamma _A)}{4G_N^{(d+2)}},\) 
